The RA-MS3 first saw use during the Outer Rim War, where it began production after an Arm infantry team salvaged an MPRL-1 Trident missile launcher used by their enemy, the USIF, and reverse-engineered it to the Arm's need of an effective anti-vehicular/infantry weapon to combat enemy mechs and tanks.

The weapon received significant improvements following the Arm of Orion's defeat in the Outer Rim War.

Instead of a charge-load chamber like the Trident, the Panther features a large box magazine containing eight missiles, as well as picatinny rails which help increase versatility. Like the Trident though, it features a retractable foregrip and a shoulder pad.

The Panther fires a shaped-charge HEAT (High-Explosive Anti-Tank) round, similar to the Trident. Upon impact, the round creates an explosion that creates a directional jet of superheated metal that burns through all known armor. Because the round is directional, the explosion generated by the round is minimized against shielded and armored targets on foot, but the impact explosion is devastating and has proven highly effective against slow-moving enemy infantry and vehicles. Splash damage is also devastating so even a near miss could cripple a structure.

Newer models retain the same basic features of the older Panther model, but feature a few aesthetic changes as well as more damaging HEAT rounds, giving the newer models greater hitting power per shot than its predecessor. However, the more damaging HEAT rounds also take up more space in the weapon's revolver clips, giving the newer Trident model only six shots per clip, compared to the older model's eight shots per clip.